Emotion is a prominent feature of life, increasingly thought to play a central role throughout the life-span in a wide range of human processes. Whereas losses are seen in many psychological and physical domains in old age, emotion may be an area of functioning that is relatively spared. Learning and experience play a critical role in many aspects of emotion, thus it is conceivable that actual gains may be seen in old age. This proposal requests support for a series of studies in which three of the most fundamental aspects of emotion--emotional reaction, emotional regulation, and emotional understanding--are studied cross-sectionally in samples of young, middle-age, and elderly individuals and longitudinally in samples of middle-aged and older individuals who will have been studied three times over a ten-year period. The proposed studies are characterized by a multi-method approach in which subjective, expressive, and physiological aspects of both positive and negative emotions are considered. Although all studies are conducted in a laboratory setting, both naturalistic and experimentally manipulated behaviors are studied. The work attempts to disambiguate several issues in the literature on emotion and age. By studying relatively non-emotional tasks (e.g., isometric exercise) and highly emotional tasks, it should be possible to separate age differences in emotional reactivity from possible age differences in non-emotional reactivity. By instructing subjects to regulate their emotions in different ways (suppress and amplify using antecedent focused, response-focused, and non-directed strategies), we will be able to determine if the capacity to control emotion increases in late life. By using an empathic accuracy task with high ecological validity and objective accuracy criteria, it should be possible to determine whether there are actual changes in one important aspect of emotional understanding--the ability to know what others are feeling--with age. By studying emotion in vivo in a longitudinal sample, we should learn whether age differences in emotional reaction and regulation previously observed in cross-sectional comparisons are also reflected within individuals over time. Finally, using the longitudinal data it should be possible to test the notion that gender differences, which are quite large in the realm of emotion early in life, diminish with age.